Electronic device

Abstract

An electronic device includes a top plate having a first surface and a second surface that is positioned at an elevation that is lower than an elevation of the first surface, the second surface extending from a first end part of the top plate to a second end part of the top plate, a bottom plate provided under the top plate, and a circuit board placed between the top plate and the bottom plate and mounted with an electronic component. The top plate has opposing first and second edges and opposing third and fourth edges that are perpendicular to the first and the second edges, the first end part being formed at the first edge and the second end part being formed at the second edge.

What is claimed is: 
     
       1. An electronic device comprising:
 a top plate having a first portion with a first upper surface, and a second portion with a second upper surface that is positioned at an elevation that is lower than an elevation of the first upper surface, the second upper surface extending from a first end part of the top plate to a second end part of the top plate, the top plate further including a plurality of recessed portions on the first portion, each of the recessed portions having a screw hole formed therethrough; 
 a bottom plate provided under the top plate; and 
 a circuit board placed between the top plate and the bottom plate and mounted with an electronic component, 
 wherein the top plate has opposing first and second edges and opposing third and fourth edges that are perpendicular to the first and the second edges, the first end part being formed at the first edge and the second end part being formed at the second edge, and 
 wherein the first upper surface is formed along an outer edge of the top plate to extend from the first edge of the top plate to the second edge of the top plate, and the second upper surface is formed at an interior portion of the top plate to extend from the first edge of the top plate to the second edge of the top plate, but neither to the third edge of the top plate nor to the fourth edge of the top plate. 
 
     
     
       2. The electronic device according to  claim 1 , wherein the first upper surface is formed on a protrusion that extends from the second upper surface. 
     
     
       3. The electronic device according to  claim 1 , wherein the first upper surface and the second upper surface form a step. 
     
     
       4. The electronic device according to  claim 1 , wherein the top plate has a rectangular shape and the first and second edges are short edges of the rectangular shape. 
     
     
       5. The electronic device according to  claim 1 , wherein the top plate has a rectangular shape and the first and second edges are long edges of the rectangular shape. 
     
     
       6. The electronic device according to  claim 1 , further comprising a plurality of heat dissipation sheets positioned between the circuit board and one or both of the top plate and the bottom plate. 
     
     
       7. The electronic device according to  claim 6 , wherein the heat dissipation sheets contact the top plate and the circuit board. 
     
     
       8. The electronic device according to  claim 6 , wherein the heat dissipation sheets contact the bottom plate and the circuit board. 
     
     
       9. The electronic device according to  claim 1 , wherein the first upper surface is formed on a plurality of protrusions, each of which extends from the second upper surface. 
     
     
       10. The electronic device according to  claim 1 , wherein one of the recessed portions is along the third edge of the top plate and one of the recessed portions is along the fourth edge of the top plate. 
     
     
       11. An electronic device comprising:
 a top plate having a first portion with a first upper surface and a second portion with a second upper surface that is positioned at an elevation that is lower than an elevation of the first upper surface, the top plate further including a plurality of recessed portions on the first portion, each of the recessed portions having a screw hole formed therethrough; 
 a bottom plate provided under the top plate; and 
 a circuit board placed between the top plate and the bottom plate and mounted with an electronic component, 
 a plurality of heat dissipation sheets positioned between and in contact with the circuit board and one or both of the top plate and the bottom plate, wherein 
 the second upper surface extends from a first end part of the top plate to a second end part of the top plate to allow for cooling air to flow from a first end of the electronic device to a second end of the electronic device, 
 the top plate has opposing first and second edges and opposing third and fourth edges that are perpendicular to the first and the second edges, the first end part being formed at the first edge and the second end part being formed at the second edge, and 
 the first upper surface is formed along an outer edge of the top plate to extend from the first edge of the top plate to the second edge of the top plate, and the second upper surface is formed at an interior portion of the top plate to extend from the first edge of the top plate to the second edge of the top plate, but neither to the third edge of the top plate nor to the fourth edge of the top plate. 
 
     
     
       12. The electronic device according to  claim 11 , wherein
 the first upper surface is formed on a plurality of protrusions, each of which extends from the second upper surface. 
 
     
     
       13. The electronic device according to  claim 12 , wherein the first upper surface and the second upper surface form a step. 
     
     
       14. The electronic device according to  claim 12 , wherein the top plate has a rectangular shape and the first and second edges are short edges of the rectangular shape. 
     
     
       15. The electronic device according to  claim 11 , wherein one of the recessed portions is along the third edge of the top plate and one of the recessed portions is along the fourth edge of the top plate. 
     
     
       16. An electronic device comprising:
 a top plate having a first portion with a first upper surface and a second portion with a second upper surface that is positioned at an elevation that is lower than an elevation of the first upper surface, the second upper surface extending from a first end part of the top plate to a second end part of the top plate, the top plate further including a plurality of recessed portions on the first portion, each of the recessed portions having a screw hole formed therethrough; 
 a bottom plate provided under the top plate; and 
 a circuit board placed between the top plate and the bottom plate and mounted with an electronic component, 
 wherein the top plate has opposing first and second edges and opposing third and fourth edges that are perpendicular to the first and the second edges, the first end part being formed at the first edge and the second end part being formed at the second edge, and 
 wherein a rib is formed on the top plate, the rib protruding from the second upper surface towards the bottom plate to form a groove on the second upper surface. 
 
     
     
       17. The electronic device according to  claim 16 , wherein
 the top plate has a generally rectangular shape, and 
 the rib has a generally rectangular shape to form a generally rectangular groove on the second upper surface that separates the second upper surface into a first portion that surrounds an outer periphery of the groove and a second portion that is interior of the groove. 
 
     
     
       18. The electronic device according to  claim 17 , wherein the top plate has a plurality of recesses, each of which is formed through the second portion of the second upper surface. 
     
     
       19. The electronic device according to  claim 18 , wherein
 the first upper surface is formed on a plurality of first protrusions which are arranged along the third edge and a plurality of second protrusions which are arranged along the fourth edge. 
 
     
     
       20. The electronic device according to  claim 19 , wherein the second upper surface extends to the third edge at portions of the top plate between the first protrusions and to the fourth edge at portions of the top plate between the second protrusions.